Abstract: Cables, as one of the most commonly used electrical equipment materials, inevitably cause fires due to overheating faults caused by harsh working environments and overload operation during operation. However, there is still a lack of economical and reliable cable fire detection methods. In the early stages of a fire, gaseous volatiles are often generated earlier than visible smoke. Therefore, this paper focuses on gaseous volatiles in the early stages of cable fires. Using polyvinyl chloride (PVC), a commonly used outer sheath material for cables, as the research object, gas chromatography-mass spectrometry (GC-MS) was employed to study the gaseous volatiles generated during its overheating and their temperature characteristics. It was found that under the area normalization quantitative method, di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP), generated at low temperatures, exhibit positive temperature characteristics. Based on these two main gas products and the broad-spectrum characteristics of gas sensors, a gas sensor array was selected and constructed, and gas response data for PVC cables under six temperature conditions were designed. Samples were classified into normal, pre-alarm, and alarm states based on their conditions, and the Extra Trees algorithm was used to classify the sample states, achieving a recognition accuracy of 98.1%.